The major, long-term goal of the proposed research is the delineation of the scope, mechanism, and synthetic utility of 1-aza-1'-oxa(3,3)sigmatropic rearrangements of N-aryl-O-vinyl- and N,O-divinylhydroxylamines (3-4). The development of a variety of procedures for the synthesis of N-aryl-and N-vinyl-hydroxylamines and for effecting O-vinylation of the hydroxylamines are important subgoals of the project. Since aromatic hydroxylamines comprise an important class of chemical carcinogens, another objective is to expand our knowledge of the chemical properties of these compounds. The proposal has been advanced that the highly exothermic 1-aza-1'-oxa(3,3)sigmatropic rearrangement may have a role in the observed biological activities of N-arylhyroxylamines and aryl nitroso compounds. The application of 1-aza-1'oxa(3,3)sigmatropic to the synthesis of a wide variety of aromatic, heterocyclic, and a liphatic organic compounds is a major goal of the research. The rearrangement of N-aryl-Q-vinylhydroxylamines is capable of introducing carbonyl-functionalized sidechains into the ortho position of aniline derivatives under exceptionally mild conditions and thereby opens a new synthetic approach to indoles and related heterocycles. For example, pyrroloindoles, which constitute the tricyclic nucleus of the mitocycin anti-tumor agents and are now readily available by this methodology, are to be modified and functionalized so as to elaborate mitomycin analogues. The extension of this chemistry to aliphatic compounds is another objective of the project. Thus, N,O-divinylhydroxylamines, generated by O-vinylation of metallated nitrones and double enolization of N,O-diacylhydroxylamines, are expected to rearrange to 1,4-dicarbonyl compounds, an overall alpha,alpha'-coupling transform.